• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1091-1093
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• 2001

The power semiconductor is widely used in the power plant or industrial field because of genealization and enlargement. It has been controlled and operated according to its own control method. Especially in case of Power plant, it plays a major role in AVR(Automatic Voltage Regulator) or electro chlorination control circuits. Generally, they used in Analog control system at above field. But each SCR current value is different because of load unbalance or switching characteristic variations, it may cause power plant unit trip or system disorder according to SCR element burn out or bad operating condition. Therefore, in this paper a development of 3 phase current balance control algorithm is described. it gets over the past analog control system limit, controls SCR gate firing angle for 3 phase current balance.

• 한국전기전자재료학회논문지
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• 제20권5호
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• pp.410-414
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• 2007

To prevent degradation of battery efficiency generated by serious current variation in rechargeable batteries, we researched a hybrid battery combining a super capacitor and a rechargeable battery. The hybrid battery shows high efficiency in a lifetime and a voltage drop. The hybrid battery was composed of a rechargeable battery, a current regulator and a super capacitor that can be used with supporting power. Before the experiment, the hybrid battery was simulated for current regulation and an electric current in a super capacitor by using the Pspice program. After that, we compared the efficiency of the hybrid battery with the efficiency of the normal battery. In this result, we demonstrated that the hybrid battery has a higher efficiency and a longer lifespan than the normal battery.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.346-350
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• 1990

This paper proposes a novel current control strategy for current regulated VSI-PWM transistor inverter. The conventional hysteresis control method has good dynamic responses. But the switching frequencies are high because it does not optimize switching patterns. Proposed current control strategy can optimize switching patterns. As regulator, three level comparators are used. The outputs of the comparators select appropriate inverter output voltage vectors via switching table stored in EPROM. The simulation and exparimental results in comparison to contentional hysteresis strategy are presented and discussed.

• 조명전기설비학회논문지
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• 제23권1호
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• pp.150-155
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• 2009

히스테리시스 전류 제어방식은 원리와 구조가 간단하여 널리 사용되었으나, 전류 오차 허용 밴드폭이 너무 작거나, 전원 전압이 상대적으로 너무 큰 경우 등에는 스위칭 주파수가 급격히 증가하여 많은 열을 발생할 수 있는 등의 단점이 있었다. 이에 본 연구에서는 단상 전류제어에서 0 모드를 추가하고, 기준 전류의 기울기를 비교하여 히스테리시스 전류 제어를 수행함으로써 대폭적인 스위칭 주파수 감소와 안정적인 전류제어가 가능하게 하였다. 또한 이를 컴퓨터 시뮬레이션을 통해 그 타당성을 확인하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권4호
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• pp.484-494
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• 2014

We describe a digitally controlled oscillator (DCO) which compensates the frequency variations for process, voltage, and temperature (PVT) variations with an accuracy of ${\pm}2.6%$ at 2.5 GHz. The DCO includes an 8 phase current-controlled ring oscillator, a digitally controlled current source (DCCS), a process and temperature (PT)-counteracting voltage regulator, and a bias current generator. The DCO operates at a center frequency of 2.5 GHz with a wide tuning range of 2.2 GHz to 3.0 GHz. At 2.8 GHz, the DCO achieves a phase noise of -112 dBc/Hz at 10 MHz offset. When it is implemented in an all-digital phase-locked loop (ADPLL), the ADPLL exhibits an RMS jitter of 8.9 ps and a peak to peak jitter of 77.5 ps. The proposed DCO and ADPLL are fabricated in 65 nm CMOS technology with supply voltages of 2.5 V and 1.0 V, respectively.

• 한국산업정보학회논문지
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• 제20권6호
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• pp.29-36
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• 2015

본 논문에서는 3개의 선형 전류 레귤레이터 그리고 자동 기준 전압 조절과 출력 전압 조절 루프를 포함하는 LED 배면광 드라이버 IC를 제안한다. 제안한 LED 드라이버에서 출력전압은 이중 피드백 루프를 통해 제어된다. 첫 번째 루프는 출력전압을 감지하고 조절하며, 두 번째 루프는 선형 전류 레귤레이터의 전압 강하를 감지하고 기준전압을 조정한다. 이러한 피드백 루프와, 선형 전류 레귤레이터의 전압강하는 드라이버 효율이 최대가 될 수 있는 최소값으로 유지된다. 드라이버의 출력은 각 채널당 4개의 LED를 가지는 3개의 채널 LED 구조이다. 휘도는 펄스 폭 변조(PWM) dimming 신호에 의해 조절된다. 제안한 드라이버는 0.35um의 60-V 고전압 공정에서 설계되었고, 측정 결과 최대 85% 정도의 효율을 가진다.

• 전력전자학회논문지
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• 제14권1호
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• pp.38-45
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• 2009

일정 출력을 얻기 위해 동기발전기 계자 여자는 AVR에 의해 제어된다. 대부분의 선박용 동기발전기 AVR은 사이리스터 위상제어 방식을 사용한다. 하지만 이 방식은 제어 주기가 MOSFET이나 IGBT로 구성된 컨버터에 비해 느리므로 속응 제어를 구현하는데 어려움이 있다. 따라서 본 논문에서는 선박용 동기발전기에 MOSFET을 사용한 PMG형 디지털 AVR을 구현하였다. PMG형 디지털 AVR 회로 구성은 간단하고 단락 시 발전기 출력전압이 영으로 되어 AVR이 동작하지 못하므로 출력전류를 여자회로로 흐르도록 하는 CBC가 요구된다. 본 논문에서 연구된 여자 시스템은 실제 선박용 발전기를 대신하여 10[kVA]급 프로토타입의 실험을 통하여 시스템의 타당성을 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.266-270
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• 2001

This paper presents a novel topological prototype of voltage source series quasi-resonant zero current soft-switching pulse frequency modulated dc-dc power converter circuit using IGBTs which incorporates a high-frequency flyback transformer link. Its steady-state operating principle is described on the basis of simulation analysis, along with the open loop controlled power regulation characteristics of the multi-functional coupled inductors linked dc-dc power converter operating under a principle of zero current soft switching commutation.

• Journal of Power Electronics
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• 제18권4호
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• pp.1165-1177
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• 2018

This paper investigates the active damping of grid-connected LCL filter resonance using high-pass filter (HPF) of the grid current. An expression for such HPF is derived in terms of the filter components. This expression facilitates a general study of the actively damped filter behavior in the discrete time domain. Limits for the HPF parameters are derived to avoid the excitation of unstable open loop poles since such excitation can reduce both the damping performance and the system robustness. Based on this study, straightforward co-design steps for the active damping loop along with the fundamental current regulator are proposed. A numerical example along with simulation and experimental results are presented to verify the theoretical analyses.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.187-192
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• 2007

The terminal voltage of a synchronous generator is maintained by the field current control of excitation system Generally AC/DC converter which is component of AVR(Automatic Voltage Regulator) system for excitation current control is connected to diode rectifier and DC/DC converter system In the case of diode rectifier system of phase controlled converter, AC/DC converter has low power factor and some low order harmonics in the line current. In this paper, two-stage three-phase PWM AC/DC converter is studied to solve these problems, The proposed method is verified by the computer simulations and experimental results in prototype generation system.